Naming arguments in Fn traits

[elichai]

Hi,
Right now If there's a Fn* trait that has 2 parameters of the same type it's really easy to confuse which is which.
i.e.:

type Callback = FnMut(&[u8], &[u8]) -> Point;

If we could name the arguments it would become easier to read and harder to misuse.

type Callback = FnMut(x: &[u8], y: &[u8]) -> Point;

[hadronized]

Here, x and y represent types. They’re type variables. Type variables should be PascalCase.

EDIT: Nah, they don’t. I was mistaken about what the author wanted to do. Sorry for the noise.

[Lokathor]

No they're not?

[petrochenkov]

Duplicate of #557 (but this issue has a better name and examples, not mentioning some pre-1.0 features).

[elichai]

Duplicate of #557 (but this issue has a better name and examples, not mentioning some pre-1.0 features).

yeah but sugar syntax for closures is a few levels above what i'm proposing.

[hadronized]

No they're not?

Yikes yeah, I was mistaken about what the OP wanted to do.

[KarelHrkal]

The "duplicate" issue is marked as completed but it doesn't work. Playground link.